As is well known, concrete has been extensively utilized as a building material for industrial, commercial and residential applications. Due to its durability, wear resistance and cost economy, concrete is currently gaining widespread use in flooring applications. With this widespread use, the public is currently demanding variations in color and surface texture of concrete such that the concrete possesses improved asthetics similar to more conventional and costly flooring surfaces such as marble, stone and granite.
To meet this demand the concrete trade has heretofore developed various coloring and surface finishing techniques to enhance the asthetics of the concrete. Examples of such finishing techniques comprise salt finish, multiple broom finish, form press finish, and exposed aggregate finish.
With specific relation to exposed aggregate finishes, basically two production methods are currently being utilized, i.e. integrally exposed aggregate and surface seeded exposed aggregate. The more conventional of these two, i.e. the integrally exposed aggregate, comprises the washing or removal of the surface cement and fines from the concrete while the concrete surface is still plastic, i.e. before full curing, such that the aggregate, normally rock or gravel, is left exposed on the surface of the concrete. Due to the normal size of such concrete aggregate being relatively large, i.e. approximately one-half to one inch in mean diameter, as well as the washing process not being uniform in nature, the resultant concrete surface derived by the integrally exposed aggregate method is extremely rough and jagged, thereby limiting its widespread use in flooring applications.
More recently, surface seeded exposed aggregate has been introduced which, subsequent to the pouring of the concrete, rock or gravel aggregate is broadcasted, i.e. seeded, over the top surface of the concrete and subsequently troweled into the same wherein upon curing the aggregate broadcast over the surface adheres to the surface and is thus exposed. Although various size aggregate can be broadcast over the surface of the concrete in the surface seeded exposed aggregate technique, normally such aggregate is approximately three-eighths inch diameter mean size or greater, having sheared or jagged edges such that the same can be worked into the surface of the concrete and be adequately adhered thereto. Thus, the resultant concrete surface, although being flater and not possessing as many surface irregularities as the integrally exposed aggregate surface, still possesses an extremely rough surface which limits its widespread use in flooring applications.
In recognizing this deficiency, attempts have been made to reduce the size of the aggregate exposed on the surface of the concrete. However, such proposed solutions have typically failed due to the inability in adhering such smaller aggregate to the concrete surface. In this regard, as the aggregate size diminishes, it has heretofore been difficult, if not impossible, in insure that the aggregate will be adequately maintained upon the surface of the concrete for prolonged duration and with substantial uniformity.
Thus, there exists a substantial need in the art for an improved exposed aggregate concrete finishing technique which maintains sufficient flatness and possesses minimal surface roughness so as to be suitable for pedestrian hihg traffic flooring applications.